The invention relates to a new and distinct cultivar of Laua'e named `Laua'e Iki`. Laua'e is an ornamental fern, Microsorium scolopendrium, of the family Polypodiaceae. Laua'e is primarily cultivated for use as ground cover, particularly in tropical regions such as Hawai'i.
The cultivar is in fact a dwarf wherein all of the usual elements of the known, standard (wild type) Laua'e fern are present but, with the exceptions of spore clusters and roots, are on a dwarf scale. Proportionally reduced or dwarfed to about 1/2 to 2/3 normal size are the leaves, stems and rhizomes.
The new cultivar was discovered in a cultivated area by the inventor in Paia, Maui, as a naturally occurring mutation of unknown origin in a population of about 10,000 Laua'e plants.
The discovery was occasioned by a distinctive growth habit whereby `Laua'e Iki` initially produces a very large number of small, juvenile, lanceolate leaves growing much closer together than is characteristic for M. scolopendrium. Through prolongation of the juvenile stage and more frequent leaf initiation, `Laua'e Iki` produces about double the number of leaves (albeit smaller) as a corresponding plant of M. scolopendrium. For example, a 1.75" by 2.5" by 3" container may contain 30 juvenile leaves of `Laua'e Iki` while normal M. scolopendrium growing from similar starting material will have but 15 leaves. The extended juvenile stage is an observed advantage for vegetative propagation as smaller leaves, rhizomes, and shorter internodes accelerate the growth sequence resulting in more plant divisions per unit of time and propagation area.
Asexual reproduction was accomplished by division of the rhizomatous rootstock at Paia. The reproduction of the variety has shown that the unique features of this new fern are stabilized and retained over eight successive generations, involving over 15,000 plants, of rhizome separation and planting. It is anticipated that other reproductive methods such as, for example, tissue culture, can also be suitably employed and are accordingly within the scope of the invention.
The cultivar `Laua'e Iki` has been observed under many environmental and growth situations without any indication of reversion to original type or further mutation into another form. It has been cultivated in small soil plots along with regular Laua'e for over two years with each cultivar remaining true to form. Over 100,000 have been observed in various stages of growth without recognizable reversion or further mutation, indicating the `Laua'e Iki` is genetically stable, and is neither common nor a recognized variant of the source plant, M. scolopendrium.
`Laua'e Iki` responds no differently than common laua'e to minor scale and aphid problems in the nursery. No other insect problems have been noted in nursery or field. No resistance or susceptibility to pathogens has been observed.
Due to its smaller size, it is expected that `Laua'e Iki` will be greatly preferred over the standard (wild type) laua'e plant for use as ornamental ground cover.
The new fern has not been observed under all possible environmental conditions. The phenotype may vary somewhat with variations in environment such as temperature and light intensity, without, however, any variance in genotype. The following observations and comparisons describe plants grown in Paia, under conditions generally used in commercial practice.